• Environmental Engineering Research
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• v.22 no.2
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• pp.162-168
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• 2017

Rainfall is one of the most important phenomena of the natural system. In Bangladesh, agriculture largely depends on the intensity and variability of rainfall. Therefore, an early indication of possible rainfall can help to solve several problems related to agriculture, climate change and natural hazards like flood and drought. Rainfall forecasting could play a significant role in the planning and management of water resource systems also. In this study, univariate Seasonal Autoregressive Integrated Moving Average (SARIMA) model was used to forecast monthly rainfall for twelve months lead-time for thirty rainfall stations of Bangladesh. The best SARIMA model was chosen based on the RMSE and normalized BIC criteria. A validation check for each station was performed on residual series. Residuals were found white noise at almost all stations. Besides, lack of fit test and normalized BIC confirms all the models were fitted satisfactorily. The predicted results from the selected models were compared with the observed data to determine prediction precision. We found that selected models predicted monthly rainfall with a reasonable accuracy. Therefore, year-long rainfall can be forecasted using these models.

• Korean Journal of Child Studies
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• v.31 no.4
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• pp.139-157
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• 2010

This study investigated the cognitive process of 5-year-old children, with a particular focus on gender, monthly age, and their tendencies towards hyperactivity through the performance of the Cognitive Assessment System (CAS; Das & Naglieri, 1997). The children with tendencies towards hyperactivity were identified based on Conners Teachers' Rating Scale (CTRS). The subjects were 75 five-year-old children in Seoul and surrounding metropolitan areas. Data were analyzed by means of descriptive statistics, an independent sample t-test, Pearson's correlation coefficient, one-way ANOVA, and by K-mean cluster analysis. Our results were as follows : (1) The CAS and CTRS' sub-factors were correlated negatively, except the positive correlation between planning factor and hyperactivity factor. (2) Girls exhibited significantly higher CAS scores in planning & sequential processing than boys. (3) The upper monthly age group (68-71 months) showed significantly higher score in terms of planning than the lower monthly age group (60-63 months). (4) The CAS scores of the children with tendencies towards hyperactivity was lower than that of normal children. (5) The CAS profile of 5-year-old children was divided into 4 groups with distinctive characteristics by means of K-mean cluster analysis.

• Journal of the Korean Home Economics Association
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• v.34 no.2
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• pp.201-215
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• 1996

The purpose of the study was to examine the effects of household characteristics to family savings. Family savings were defined in four ways such as monthly savings, average propensity to save, financial assets, and net financial assets. The household characteristics dealt with were family income, household size, number of earners, age, occupation, education, housing tenure, and urbanization. The data used in the study was Survey of Family Finance 1990. The main statistical method was multiple regression. Family income was found to the most important variable to determine four family saving variables holding other characteristics constant. Also, household size had significant negative effects on family savings. Two-earner households were found to have higher average propensity to save and less financial assets compared to single-earner households. Fro monthly savings and average propensity to save, the households with forties andfifties household head tended to be less than others, while financial assets tended to increase with the age of household head. Compared to salary earner households, blue-colored households had significantly lower average propensity to save, and the households with professionals had significantly higher financial assets. The college-graduated households tended to have less monthly savings than the elementary-graduated households. Also, the housing renters were found to have more monthly savings and higher average propensity to save, compared to the housing owners.

• Journal of the Korean Home Economics Association
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• v.40 no.7
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• pp.211-227
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• 2002

The issue of children′s education is the most important issue for all households in Korea. It is certain that the issue of private education for children is the first issue among household′s issues. This study is to recognize the current pictures of household primate education of Korean households. Also, whether the expenditure of private education effect the economic will-being of household. The data for this study was"the 3th Korean Labor Panal", conducted by Lobor in Korea. The sample was 1950 households from the panel data. The results of this study was as following: 1. The mean of monthly private education expenditure was 149273won for all households and 217,100won for households with high school students. 2. Almost 70% households had economic burden for private education expenditure. 0% households had no economic burden. 3. The factors of influencing the level of economic burden for private education were mother′s education level, mother′s job, the number of children, living location, monthly income, total asset of household′s. The factors of influencing the amount of monthly private education expenditure positively were living in 4. The economic well-being of household was analyzed by socio-economic variables, household′s financial variables, monthly private education expenditure, the level of economic burden of private education. The economic well-being were sub-categorized 4 divisions; the level of economic problem, the level of satisfaction for household′s income, the level of satisfaction for general living, the level of subject economic condition)

• Journal of the Korean housing association
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• v.23 no.1
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• pp.9-17
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• 2012

The purpose of this study is to understand the factors that influence residents' satisfaction with their housing. Resident's satisfaction is mainly influenced by two factors - one that pertains to housing and the other as per characteristics of the individual. Housing-related factors include housing types, housing tenure types, and size of floor space. Individual-related factors include household income, size, and education level. This study shows how both factors influence residents' satisfaction. Residential satisfaction is affected by the type of housing tenure (own, chonsei and monthly rent) and housing (detached housing, apartment and multi-family housing). Residential satisfaction of home owners is greater than that of chonsei renters or monthly renters. Residential satisfaction of chonsei renters is greater than that of monthly renters. Satisfaction of apartment residents is far greater than that of detached housing residents or multi-family housing residents. There is no difference in residential satisfaction between detached housing and multi-family housing residents. As total household labor income, household member, and residential area increase, residential satisfaction increase. Residential satisfaction of countryside residents is greater than that of metropolitan residents.

• The Korean Journal of Malacology
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• v.22 no.2
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• pp.143-150
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• 2006

The gonad index, condition index, reproductive cycle and spawning of the pen shell Atrina (Servatrina) pectinata were investigated using samples from the subtidal zone of Nokdo on the Boryeong coastal waters of Korea. Samples were collected monthly by SCUBA divers for one year from January to December, 2001. A. (Servatrina) pectinata is dioecious and oviparous. The spawning season of this species occurred once a year from June to August, with the main spawning occurring between June and July when the seawater temperature was around $20^{\circ}C$. Ripe oocytes were about 60-65 ${\mu}m$ in diameter. The reproductive cycle of this species could be classified into five successive stages; early active stage (November to March), late active stage (February to May), ripe stage (April to July), partially spawned stage (June to August), and spent/inactive stage (August to October). Monthly changes in the gonad index reached a maximum (4.6) in May (ripe stage), thereafter, the GI values gradually decreased from June to August when spawning occurred continuously. Therefore, monthly changes in the GI values showed a similar pattern to the gonadal phase. The condition index (CI) of the meat part without the posterior adductor muscle reached the maximum in June (ripe and partially spawned stage) and the minimum in September (spent/inactive stage), Accordingly, monthly changes in the condition indice of the meat part without the posterior adductor muscle coincided with the gonadal phases.

• Water for future
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• v.23 no.1
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• pp.99-107
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• 1990

The statistical analysis based on the past hydrologic data required to set up the water resources development plan and design the hydraulic structres rationally. Because hydrologic events have random factors implied, the sotchastic analysis is necessary. In this paper, same order of stochastic models of monthly runoff data(multivariate AR(1) and AR(2) models, univariate AR(1) and AR(2) models) are applied to compare the statistical characteristics. The other purpose of this paper is to compare the monthly series, which is generated by univariate and multivariate models. By comparing and estimating of each simulated series, it is known that the multivariate models, including the time and spatial colinearity, are better in prediction than univariate models in the analysis of monthly flow at south Han river basin.

• Water for future
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• v.24 no.4
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• pp.67-72
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• 1991

Various modeling approaches to study along term behavior of streamflow or groundwater storagge have been conducted. In this study, a Multivariate AR (1) Model has been applied to generate monthly flows of the one key station which has historical flows using monthly flows of the three subordinate stations. The Model performance was examined using statistical comparisons between the historical and generated monthly series such as mean, various, skewness. Also, the correlation coefficients(lag-zero, and lag-one)between the two monthly flows were compared. The results showed that the modeled generated flows were statistically similar to the historical flows.

• Water for future
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• v.24 no.4
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• pp.85-91
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• 1991

An effort was made to develop a monthly runoff predition method based on the Thomas model. For the 20watersheds selected the Thomas model was fitted, the parameters being determined by the Rosenbrok's rotating coordinate search method using the monthly rainfall and runoff data. The so determined parameters were correlated with the meteorologic, topographic and geologic characteristics of the watersheds. The model was tested by comparing the observed and simulated monthly runoff records from two test watersheds. The result showed that the model developed in the present study could satisfactorily be applied to ungauged watersheds It was noticed that the model had the tendency of slightly overestimating the runoff during winter periond and underestimating during the spring period.

• Journal of Industrial Convergence
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• v.7 no.1
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• pp.63-82
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• 2009

Many The purpose of this paper is to revisit the existence of monthly effect in the Korea Stock Market. We conducted additory test about KOSPI200 from January 1990 to December 2002 and about KOSDAQ from January 2002 to December 2006. The other main focus is examine Size Effect in Korean Stock Market. We also indicate Information hypothesis throught our findig. Data used in this paper are monthly returns of KOSPI and KOSDAQ from 1980 to 2006. As a result, Evidence is provided that monthly abnormal returns in January have large means relative to the remaining eleven months. The relation between abnormal returns and size is always negative and more pronounced in January than in any other month-even in years. More than fifty percent of the January premium is attributable to large abnormal returns during the first week of trading in the year particularly on the first trading day. This finding is highly significant in the mall sized capital stock of KOSPI market. We found January effect and Size Effect in the KOSPI market, but we didn't find January effect and Size Effect in the KOSDAQ market and KOSPI200.